Q. I have used polybutylene piping in many of my construction projects ( including my own home). After reading about a pending class-action lawsuit against the piping manufacturers, I’m concerned, and I don’t feel I’m getting the straight story from my plumbers or supply houses. Have I unknowingly created a time bomb?

A.Dan Friedman responds: Polybutylene (PB) piping has been used since the mid-1970s for water supply and in-house supply piping. Two types of PB piping failures have led to class-action lawsuits against PB plumbing manufacturers: leaks due to improper installation and leaks due to defective materials.

Early failures were found in Celcon acetyl-plastic insert fittings (tees and elbows) used for connections. A portion of the insert fitting is inserted into the pipe and then clamped in place using an aluminum or copper crimp ring over the outside of the pipe. Leaks have also occurred with the more recent copper and brass insert fittings. While the earlier fitting failures were attributed in part to defective material, the PB industry blames current fitting leaks on improper installation.

The industry has taken a number of steps to reduce failures, which include detailed installation instructions, a redesigned crimping tool, a "go/no-go" gauge, and a suggestion to use metal insert fittings and annealed-copper crimp rings. These recommended methods and materials have significantly reduced problems, and some builders are still installing PB piping in new construction.

But a second problem may be looming. Testimony from a class-action lawsuit, a 1991 60 Minutes program, and an installation instruction booklet all indicate that the piping itself may crack and leak in some conditions. PB piping may be particularly vulnerable where higher levels of chlorine are present in the water supply. If you’ve installed this material in environments where there are elevated levels of chlorine, the risk of future leaks is greater.

A PB-related class-action lawsuit has been filed, and preliminary approval of the settlement has been granted. You may want to reduce your own risk and improve relations with your customers by warning them of your concern, and providing them with contact information regarding the class-action lawsuit. If a qualifying leak has already occurred, deadlines for submitting claims are as early as August 21, 1996.

For more information, contact the Industry-PB Technology Center at 800/338-7732, or for information about the class-action settlement agreement, the Consumer Plumbing Recovery Center at 800/876-4698.

Those with World Wide Web access can view the class-action notice at: http://www.hunt.com/polybutylene/pipe/notice.htm and the class-action proposed settlement at http://www.hunt.com/polybutylene/pipe/propset.htm. To see photos that will help you identify the materials involved, see http://www.hunt.com/polybutylene/pipe/pipe.htm.

Dan Friedman operates American Home Service Co., a residential and commercial property inspection service in Poughkeepsie, N.Y.